Is there room for more than one Pinterest?

We Heart It, a mood board site similar to Pinterest, has followed an unusual startup trajectory. It was created in 2008 before Pinterest, by a Brazil-based design student who wanted a place online to collect images to spark his creativity. The site took off on its own, growing steadily through word of mouth without marketing.

Maintaining it was taking time, energy, and money, particularly once the designer Fabio Giolito brought on a technical co-founder. Giolito, not from a traditional Silicon Valley background, considered shutting it down. It was only meant to be a side project, after all.

As a last ditch resort, he emailed his contacts in the US tech world who told him, "Whatever you do don't shut it down. We'll help you find funding." They tapped their contacts and Giolito raised some seed money from angels and other entities in 2011, a year after Pinterest launched.

The site survived, continued growing, and a few months ago announced it had raised an $8 million round from White Oak and IDG Ventures. Mere pennies compared to the total $338 million Pinterest has raised after its most recent funding round, reported by AllThingsD yesterday.

But here's the compelling part: We Heart It has 20 million monthly active users, whereas Pinterest has 50 million monthly active users according to AllThingsD. We Heart It is catching up.

The growing success of We Heart It and its monthly active user count suggests one thing: there's room for more than one Pinterest on the market. And if investors are willing to bet that big on Pinterest, perhaps they'll start making bigger bets on the Pinterest competitors too.

We Heart It is a social scrapbooking site, where people pin inspirational, thoughtful, or beautiful images. Users can follow each other or 'heart' each others images, but comments are disabled. CEO Ranah Edelin believes this keeps trolling and cyberbullying off the site and maintains its positive tone.

Although there are some differentiators between Pinterest and We Heart It, the functionalities are very similar. People 'heart' images on the web to pull them onto their We Heart It mood board, much like 'pinning.' People use We Heart It for inspiration and visual exploration, much like Pinterest.

It's a noteworthy point given that Pinterest raised its latest $225 million round with no actual revenue yet, bringing its total valuation up to $3.8 billion.

Investors are making big bets on the visual web. Pinterest and its competitors are Instagrams perfectly designed as advertising vehicles. People pin the clothes, places, food, and lifestyles they aspire to and 'promoted pins' from marketers can sit perfectly beside those wishes, hopes, and dreams.

The We Heart It demographic skews much younger than Pinterest -- 16-24, that target age group that makes advertisers salivate. When I made the Pinterest comparison, Edelin was quick to draw distinctions.

"Our users say, 'Pinterest -- that's that craftsy DIY service that my aunt uses," Edelin says. He points out that the two sites have very different origins. One was started by a design student who wanted artistic stimulation, the other by an entrepreneur looking for a hot idea, inspired by his childhood bug collections.

As a result, Edelin believes that We Heart It serves as more of a mood board for a user's momentary thoughts and feelings, whereas Pinterest is more of a place for pinning objects and things. "When the Boston bombings happened, on We Heart It people expressed how they felt through images. 'We heart Boston,' 'We pray for Boston,'" Edelin says. "If you went on Pinterest and searched for Boston it's things people could buy related to Boston merchandise."

It might be in Edelin's favor to paint Pinterest that way, but I think the site has broadened greatly from its 'collector' origins. I consider Pinterest a mood board, inspiration board, product finder, and scrapbook all rolled into one.

So, Pinterest is the old timey aunt with the strongest market grip on the web scrap boarding space. We Heart It is the younger, up and coming rival. And then there's hipster newby Twibfy, which I wrote about a few months ago.

Twibfy was started by a few ad agency creatives in Holland who also wanted a place for visual inspiration. They needed mood boards on demand to kickstart their thoughts for the visual advertising campaigns they produce.

Pinterest didn't do the trick for them because they wanted a curated space. One where the 'bad' images would be weeded out and only the beautiful, weird, compelling, ugly, potent images would remain. They also wanted it searchable by color or object. That way if they were doing an advertising campaign for a "red car" they could search "red car" and get kernels of inspiration for the aesthetic of the campaign.

Twibfy is still new but it's been quietly chugging along without venture funding, and is the third Pinterest on the market.

All three -- We Heart It, Pinterest, and Twibfy -- offer slightly different communities and are powered by different purposes. Is there room for all of them?

The visual web, what with Instagram and SnapChat, has certainly taken off. People turn to pictures to represent themselves, communicate, seek inspiration or understanding, and explore.

And the pictures themselves are excellent vehicles for marketers looking to spend money. Ads can be quietly slipped in alongside user's 'inspirations.' Then, instead of people glossing over the banners, they take them in with all the rest of the scrapbook visuals.